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From:   Tedd Ho-Jeong An <hj.tedd.an@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     Tedd Ho-Jeong An <tedd.an@intel.com>
Subject: [RFC PATCH] Bluetooth: vhci: Add new packet type for VHCI
Date:   Thu, 28 Oct 2021 23:13:45 -0700
Message-Id: <20211029061345.676005-1-hj.tedd.an@gmail.com>
MIME-Version: 1.0
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From: Tedd Ho-Jeong An <tedd.an@intel.com>

Current implementation uses the Vendor packet type (0xff) with opcode
parameter. But there is no way to expand the opcode and no available bits
to use. Also it cannot be changed due to the backward compatibility
with older kernel.

So, this patch adds new packet type dedicated for VHCI(0xfe) to support
configuring the VHCI device with quarks and flags while creating the
VHCI driver.

Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
---
 drivers/bluetooth/hci_vhci.c | 161 ++++++++++++++++++++++++++++++-----
 include/net/bluetooth/hci.h  |   1 +
 2 files changed, 140 insertions(+), 22 deletions(-)

diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
index 49ac884d996e..4ae1e861b3a8 100644
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -30,6 +30,20 @@
 
 static bool amp;
 
+struct vhci_ext_create_device_req {
+	__u8	dev_type;
+	__u32	flags;
+} __packed;
+
+#define VHCI_FLAG_QUIRK_RAW_DEVICE		0x01
+#define VHCI_FLAG_QUIRK_EXTERNAL_CONFIG		0x02
+#define VHCI_FLAG_QUIRKS_INVALID_BDADDR		0x04
+
+struct vhci_ext_create_device_resp {
+	__u8	dev_type;
+	__u16	index;
+} __packed;
+
 struct vhci_data {
 	struct hci_dev *hdev;
 
@@ -278,6 +292,38 @@ static int vhci_setup(struct hci_dev *hdev)
 	return 0;
 }
 
+static void vhci_create_debugfs(struct hci_dev *hdev)
+{
+	struct vhci_data *data = hci_get_drvdata(hdev);
+
+	debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
+			    &force_suspend_fops);
+
+	debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
+			    &force_wakeup_fops);
+
+	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
+		debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
+				    &msft_opcode_fops);
+
+	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
+		debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
+				    &aosp_capable_fops);
+}
+
+static void vhci_setup_hdev(struct hci_dev *hdev)
+{
+	hdev->open  = vhci_open_dev;
+	hdev->close = vhci_close_dev;
+	hdev->flush = vhci_flush;
+	hdev->send  = vhci_send_frame;
+	hdev->get_data_path_id = vhci_get_data_path_id;
+	hdev->get_codec_config_data = vhci_get_codec_config_data;
+	hdev->wakeup = vhci_wakeup;
+	hdev->setup = vhci_setup;
+	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
+}
+
 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 {
 	struct hci_dev *hdev;
@@ -313,15 +359,7 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 	hdev->dev_type = dev_type;
 	hci_set_drvdata(hdev, data);
 
-	hdev->open  = vhci_open_dev;
-	hdev->close = vhci_close_dev;
-	hdev->flush = vhci_flush;
-	hdev->send  = vhci_send_frame;
-	hdev->get_data_path_id = vhci_get_data_path_id;
-	hdev->get_codec_config_data = vhci_get_codec_config_data;
-	hdev->wakeup = vhci_wakeup;
-	hdev->setup = vhci_setup;
-	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
+	vhci_setup_hdev(hdev);
 
 	/* bit 6 is for external configuration */
 	if (opcode & 0x40)
@@ -339,19 +377,7 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 		return -EBUSY;
 	}
 
-	debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
-			    &force_suspend_fops);
-
-	debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
-			    &force_wakeup_fops);
-
-	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
-		debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
-				    &msft_opcode_fops);
-
-	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
-		debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
-				    &aosp_capable_fops);
+	vhci_create_debugfs(hdev);
 
 	hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
 
@@ -364,6 +390,67 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 	return 0;
 }
 
+static int __vhci_ext_create_device(struct vhci_data *data, __u8 dev_type,
+								__u32 flags)
+{
+	struct hci_dev *hdev;
+	struct sk_buff *skb;
+	struct vhci_ext_create_device_resp *resp;
+
+	if (data->hdev)
+		return -EBADFD;
+
+	if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP)
+		return -EINVAL;
+
+	skb = bt_skb_alloc(sizeof(*resp) + 1, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdev = hci_alloc_dev();
+	if (!hdev) {
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+
+	data->hdev = hdev;
+
+	hdev->bus = HCI_VIRTUAL;
+	hdev->dev_type = dev_type;
+	hci_set_drvdata(hdev, data);
+
+	vhci_setup_hdev(hdev);
+
+	/* Check quirks and set it for hdev */
+	if (flags & VHCI_FLAG_QUIRK_EXTERNAL_CONFIG)
+		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
+
+	if (flags & VHCI_FLAG_QUIRK_RAW_DEVICE)
+		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
+
+	if (flags & VHCI_FLAG_QUIRKS_INVALID_BDADDR)
+		set_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks);
+
+	if (hci_register_dev(hdev) < 0) {
+		BT_ERR("Can't register HCI device");
+		hci_free_dev(hdev);
+		data->hdev = NULL;
+		kfree_skb(skb);
+		return -EBUSY;
+	}
+
+	vhci_create_debugfs(hdev);
+
+	hci_skb_pkt_type(skb) = HCI_VHCI_PKT;
+	skb_put_u8(skb, HCI_VHCI_PKT);
+	skb_put_u8(skb, dev_type);
+	put_unaligned_le16(hdev->id, skb_put(skb, 2));
+	skb_queue_tail(&data->readq, skb);
+
+	wake_up_interruptible(&data->read_wait);
+	return 0;
+}
+
 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
 {
 	int err;
@@ -375,6 +462,18 @@ static int vhci_create_device(struct vhci_data *data, __u8 opcode)
 	return err;
 }
 
+static int vhci_ext_create_device(struct vhci_data *data, __u8 dev_type,
+								__u32 flags)
+{
+	int err;
+
+	mutex_lock(&data->open_mutex);
+	err = __vhci_ext_create_device(data, dev_type, flags);
+	mutex_unlock(&data->open_mutex);
+
+	return err;
+}
+
 static inline ssize_t vhci_get_user(struct vhci_data *data,
 				    struct iov_iter *from)
 {
@@ -429,6 +528,24 @@ static inline ssize_t vhci_get_user(struct vhci_data *data,
 		ret = vhci_create_device(data, opcode);
 		break;
 
+	/* This packet type is for VHCI specific command */
+	case HCI_VHCI_PKT:
+		cancel_delayed_work_sync(&data->open_timeout);
+		struct vhci_ext_create_device_req *req;
+
+		if (skb->len != sizeof(*req)) {
+			kfree_skb(skb);
+			return -EINVAL;
+		}
+
+		req = (void *)skb->data;
+		skb_pull(skb, sizeof(*req));
+
+		ret = vhci_ext_create_device(data, req->dev_type, req->flags);
+
+		kfree_skb(skb);
+		break;
+
 	default:
 		kfree_skb(skb);
 		return -EINVAL;
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 63065bc01b76..35d720f9e17a 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -355,6 +355,7 @@ enum {
 #define HCI_EVENT_PKT		0x04
 #define HCI_ISODATA_PKT		0x05
 #define HCI_DIAG_PKT		0xf0
+#define HCI_VHCI_PKT		0xfe
 #define HCI_VENDOR_PKT		0xff
 
 /* HCI packet types */
-- 
2.25.1